Question

Determine o conjunto solução das seguintes equações:
a) $\left[\begin{array}{ccc}1&x&1\\-2&-4&2\\4&8&3\end{array}\right] = 0$

b)$\left[\begin{array}{ccc}-3&4&x\\5&0&0\\2&1&2\end{array}\right] = 0$

c)$\left[\begin{array}{ccc}-2&1&x\\1&2&4\\3&-1&-2\end{array}\right] = -7$

d)$\left[\begin{array}{ccc}2x&-3&0\\0&1&-2\\3&-1&4\end{array}\right] = 26$

Answer 1

a) -12+8x-16+16-16+6x=0
                                14x-28=0
                                 14x=28            x=2

b)8+12-x-6x-8+2=0
                                    -7x+14=0
                                     -7x=-14             x=2

c)8+12-x-6x-8+2=-7
                                              -7x+14=-7
                                              -7x=-7-14
                                              -7x=-21       x=3

d)8x+18-4x=26
                                            4x+18=26
                                            4x=26-18
                                            4x=8      x=2